Auxiliary locking mechanism

ABSTRACT

The lock of my prior U.S. Pat. Nos. 2,608,085 and 3,751,949 is improved by providing an auxiliary locking mechanism which is seated in the access aperture for the main lock to prevent picking and vandalizing of the main lock. The auxiliary mechanism includes a hollow two-piece housing having a periphery which is longer in one dimension than the other and which matches the contour of the main lock access opening. A first housing member seats snuggly in the main lock access aperture; the second housing member extends into the actuator slot of the main lock bolt and is rotatable relative to the first housing member so that the auxiliary mechanism cannot be removed when the two housing members are positioned 90* out of alignment. A bar extends through the hollow region of both housing members and is fixedly secured to the second housing member so that rotation of the bar produces rotation of the second housing member relative to the first. Rotation of the bar is effected by a slotted hollow shaft which is inserted into the hollow first housing member to fit over the bar so that its slot engages an actuator pin projecting radially from the bar. The slotted hollow shaft is preferably part of the handle of the key member for the main lock.

United States Patent 11 1 Castle 1 1 AUXILIARY LOCKING MECHANISM [76] Inventor: Alfred B. Castle, 4104 Maryland Ave, Brookmont, Washington, DC. 20016 [22] Filed: Nov. 19, 1973 [2]] Appl. No.: 417,200

Primary ExaminerAlbert G. Craig, Jr. Attorney, Agent, or FirmRose & Edell [57] ABSTRACT The lock of my prior US. Pat. Nos. 2,608,085 and 1 1 July 15, 1975 3,751,949 is improved by providing an auxiliary locking mechanism which is seated in the access aperture for the main lock to prevent picking and vandalizing of the main lock. The auxiliary mechanism includes a hollow two-piece housing having a periphery which is longer in one dimension than the other and which matches the contour of the main lock access opening. A first housing member seats snuggly in the main lock access aperture; the second housing member extends into the actuator slot of the main lock bolt and is rotatable relative to the first housing member so that the auxiliary mechanism cannot be removed when the two housing members are positioned 90 out of alignment. A bar extends through the hollow region of both housing members and is fixedly secured to the second housing member so that rotation of the bar produces rotation of the second housing member relative to the first. Rotation of the bar is effected by a slotted hollow shaft which is inserted into the hollow first housing member to fit over the bar so that its slot engages an actuator pin projecting radially from the bar. The slotted hollow shaft is preferably part of the handle of the key member for the main lock.

10 Claims, 8 Drawing Figures AUXILIARY LOCKING MECHANISM BACKGROUND OF THE INVENTION The present invention relates to an improvement for the locking devices disclosed in my U.S. Pat. Nos. 2,608,085 and 3,751,949 whereby an auxiliary locking mechanism is employed to prevent access to the bolt of the main locking device.

The locking device disclosed in my U.S. Pat. No. 2,608,085 includes a sliding bolt which is axially urged into a locking position by a compression spring. The bolt includes an axially extending aperture having an inclined rear wall. The aperture is accessible by means of a relatively short slot through which a combination handle-key member is inserted lengthwise. The handlekey member includes a curved surface arranged to engage the inclined rear wall of the bolt aperture when a stop in the form of a cross piece in the handle-key member abuts the slot periphery. When the handle-key member is pivoted about the stop, the curved surface of that member urges the inclined wall of the bolt rearwardly in opposition to the compression spring. When the retracted bolt clears its keeper, the handle-key member is utilized as a handle to pull the lock (and the panel or other closure to which it is secured) in a direction perpendicular to the bolt access.

In my U.S. Pat. No. 3,751,949 the locking device is modified by providing in the bolt a notch which is arranged to engage the rear wall of the lock housing when the bolt is in its lock position. In addition, the compression spring which surrounds the rearward portion of the bolt is biased against the lock housing to urge the notch into secure engagement with the rear wall of the housing and thereby prevent inadvertent axially movement of the bolt.

The locking devices of my prior Patents are quite secure and relatively tamper proof. For example, unauthorized personnel inserting a straight-edge tool into the slot cannot gain the leverage necessary to urge the inclined wall of the bolt rearwardly against the action of the spring. Moreover, a properly curved tool, configured to engage the inclined wall of the bolt aperture, would be useless it also included a properly positioned stop about which this tool could be pivoted. Still further, engagement between the notched bolt and the lock housing prevents inadvertent axial motion of the bolt from its locked position for all practical purposes. Nevertheless, for many applications there is a requirement that access to the bolt be prevented whenever the mechanism is in its locked condition. For example, electric power companies often require that locks for enclosures at high voltage field installations be vandalproof to protect against the possibility that children and other unauthorized personnel cannot gain entrance into the enclosure and have access to the dangerous high voltage equipment.

It is therefore an object of the present invention to provide an improvement of my patented locking mech anism whereby access to the main lock bolt is prevented whenever the lock is closed.

SUMMARY OF THE INVENTION The auxiliary locking mechanism of the present invention includes two hollow housing members arranged end to end and relatively rotatable to one another. When the two housing members are angularly aligned the mechanism can be inserted into the access aperture of the main lock with one of the housing members extending into the slot in the main lock bolt. An actuator bar extends axially through the hollow housing members and is secured to said one housing member for rotation therewith. Rotation of the bar is produced by a slotted hollow shaft which is inserted into the hollow housing to fit over the bar so that its slot engages an actuator pin extending radially from the bar. The slotted hollow shaft is preferably the handle portion of the handle-key member for the main lock.

BRIEF DESCRIPTION OF THE DRAWINGS The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of specific embodiments thereof, especially when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a plan view in section of my patented locking member showing the auxiliary mechanism of the present invention secured in place;

FIG. 2 is a view taken along lines 2-2 in FIG. I and illustrating the auxiliary locking mechanism in its locked condition;

FIG. 3 is a view similar to that in FIG. 2 but showing the auxiliary locking mechanism of the present invention in its open condition;

FIG. 4 is a view in section of the auxiliary locking mechanism of the present invention taken along lines 44 of FIG. 1 and showing the auxiliary locking mechanism in its locked condition;

FIG. 5 is a view in section taken along lines 55 in FIG. 4',

FIG. 6 is a view in section taken along lines 6-6 of FIG. 5;

FIG. 7 is a view in section taken along lines 77 in FIG. 5; and

FIG. 8 is a view in perspective showing the auxiliary locking mechanism of the present invention engaged by the handle of the handle-key member for the main lock.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring specifically to FIG. I of the accompanying drawings, the primary locking mechanism 20 described in U.S. Pat. No. 3,751,949 is shown modified to accept and cooperate with the auxiliary locking mechanism of the present invention. Primary locking mechanism 20 includes a U-bracket 40, the base of which is secured to base plate 41. The base plate in turn is secured to the inside surface of a hinged panel or door 10 which provides the necessary closure for the access opening into an enclosed cabinet or other enclosure I I. A recessed area 12 in the cabinet wall is configured to receive panel 10 in the closed position.

Key access slots 42, 43 and 44 are defined through panel 10, base plate 41 and bracket 40 and are aligned to form an access opening for a key handle of the type illustrated in FIG. 8. In the primary locking mechanism 20 modified according to the present invention, access slot 42, which is defined through panel 10, is larger than access slots 43 and 44 for purposes to be described below in reference to auxiliary locking mechanism 100.

A bolt 21 is mounted in U-bracket 40 for axially slidable movement in a direction generally parallel to the plane of panel 10. The opposing upstanding sides of U- bracket 40 are provided with apertures 45 and 46 which are arranged to receive the forward and rearward sections, respectively of bolt 21.

The forward or latching section 51 of bolt 21 is generally cylindrical and includes a conventional inclined surface 52 oriented to slide along an edge 53 of a keeper 23 in a camming operation during closing of panel so that the bolt is forcibly retracted until it clears edge 53. Keeper 23 is secured to cabinet 11 and is arranged to engage forward section 51 of bolt 21 in a locking engagement when panel 10 is closed. In this condition, forward section 51 of the bolt extends through aperture 45 in the forward leg of U-bracket 40.

Bolt 21, immediately rearward of forward section 51, includes an enlarged intermediate section 54 of generally rectangular configuration and disposed between the upstanding legs of the U-bracket. The transition between forward section 51 and intermediate section 54 of the bolt is defined by a shoulder 55 which normally abuts the forward leg of the U-bracket but is sufficiently large to prevent passage of section 54 through aperture 45. Intermediate section 54 of the bolt includes a through-slot or aperture 56 extending along the longitudinal axis of the bolt. The rear wall 50 of slot 56 is inclined in a rearward direction away from the bottom wall of U-bracket 40 in the same manner and for the same purpose as disclosed in my aforementioned patents. The sidewalls defining aperture 56 include opposed recesses 10] which are aligned with access slots 42, 43 and 44 when bolt 21 is in its closed position. The purpose of recessed portions 101 is described subsequently in relation to the auxiliary locking mechanism 100.

The rearward section 57 of bolt 12 is generally cylindrical and of sufficiently small diameter to extend through aperture 46 in the rearward leg of U-bracket 40. The portion of rearward section 57 which resides forwardly of aperture 46 is surrounded by a helical compression spring 60 which is compressed between the rearward edge of intermediate section 54 and the rearward leg of bracket 40. In this manner, bolt 21 is continuously biased towards its extended or locked position by spring 60. The end of rearward section 57 is bifurcated to form a knuckle joint with a projecting segment 24 of a pivot arm 25. Pivot arm 25 forms part of a three point locking device described in my aforementioned U.S. Pat. No. 3.75l.949 and forms no part of my present invention.

A channel or slot is defined in the upper surface (as viewed in FIG. 1) of rearward section 57 of the bolt. Channel 58 is disposed crosswise to the axis of the bolt and is arranged to engage the rearward leg of U- bracket 40. More particularly, the width of channel 58 is just slightly greater than the thickness of the rearward of bracket 40. Channel 58 is disposed such that when shoulder 55 abuts the forward leg of U-bracket 40, channel 58 is aligned with aperture 46. In this position, if rearward section 57 is urged upwardly, or away from panel 10, channel 58 firmly engages the bracket and prevents axial movement of the bolt. The upward urging of rearward section 57 is provided by helical spring 60, the rearward end of which is wrapped around rearward leg of bracket 40 so as to urge spring 60 away from panel 10. The rearward portion of spring 60 thus assures proper engagement by channel 58 when bolt 21 is in its locked position.

Key handle 65, illustrated in FIG. 8, is specially configured to open primary locking mechanism 20. The key-handle is a rod of basically rectangular crosssection having a straight section 66 at one end and a curved section 67 somewhat similar to a C- configuration at its other end. A grip 68 in the form of a hollow cross-bar extends through straight section 66 proximate the end of the key handle. The extreme end 70 of curved section 67 is contoured to provide a camlike surface for engaging inclined wall at the rear of slot 56. A stop 69, in the form of a cross bar, is located at curved section 67 and serves to limit the extent to which curved section 67 of the key-handle may be inserted through access openings 42, 43 and 44 of pri mary locking mechanism 20.

When bolt 21 is fully extended to its locked position (as illustrated in FIG. 1), forward section 51 of the bolt is engaged by keeper 23 while channel 58 in the bolt engages bracket 40. Keeper 23 cooperates with bolt 21 in the usual manner to prevent panel 10 from opening as long as the bolt is fully extended. A combined action of the axial force applied to the bolt by spring and the transverse force urging channel 58 into engagement with the bracket prevents any inadvertent axial movement of bolt 21.

To open locking mechanism 20, in the absence of auxiliary locking mechanism 100, curved section 67 of key-handle is inserted through slots 42, 43 and 44 into aperture 56 of the bolt. The key-handle is inserted until end contacts inclined wall 50 and stop 69 abuts the outer surface of panel 10. The key-handle is then rotated about stop 69 so that cam surface 70 pushes against and slides along inclined wall 50. This interaction between cam surface 70 and wall 50 forces bolt 21 downwardly at first (as viewed in FIG. 1) to clear channel 58 from engagement with the bracket. When channel 58 is cleared from such engagement, the bolt is forced rearwardly and retracts forward section 51 from keeper 23. Key-handle 65 is then pulled in a direction perpendicular to the panel (downward in FIG. 1) to swing the panel open.

Auxiliary locking mechanism is intended to be locked in place in slots 42, 43 and 44 to prevent unauthorized access to bolt 21 of the primary locking mechanism. Mechanism 100, as best illustrated in FIGS. 2-8, includes two hollow housing members 102 and 103 which are positioned end-to-end and are rotatable relative to one another about a common axis. One end 104 of housing member 102 is generally circular in crosssection and is configured to fit snuggly within circular slot 42 in panel 10. The remainder of member 102 and all of member 103 have a generally rectangular crosssectional periphery, the shorter edges of the rectangle being slightly arcuate to match the arcuate contour of recesses 101 in aperture 56 of the bolt. The axially length of housing member 102 is substantially equal to the combined thicknesses of panel 10, base plate 41 and the base of U-bracket 40', thus, only housing member 103 extends beyond the base of bracket 40 into aperture 56 of bolt 21 when auxiliary locking mechanism 100 is fully inserted through slots 42, 43 and 44.

It is to be noted that slot 42 has a generally circular contour so that circular end 104 of housing member 102 fits snuggly therein. Slots 43 and 44, on the other hand, have generally rectangular contours to permit them to receive the remainder of housing member 102 and housing member 103 when these members are in angular alignment. When auxiliary locking mechanism 100 is inserted through slots 42, 43 and 44 and housing member 103 is rotated 90 relative to housing member 102, mechanism 100 cannot be withdrawn from the primary locking mechanism because the mis-aligned portions of housing member 103 abut the base of U- bracket 40. The mechanism for so rotating housing member 103 is described in the following paragraphs.

A generally cylindrical locking bar 105 extends axially through the centers of hollow housing members 102 and 103. Significant axial movement of bar 105 relative to the housing member 102 is prevented by a pair of retainer pins 106 which extend transversely across opposite sides of the central bore hole in housing member 102. Retainer pins 106 are positioned in an annular recess defined between a pair of spaced annular shoulders 107 extending radially from bar 105, affording only a small degree of play in the axial position of the locking bar. The diameter of shoulders 107 corresponds to the diameter of the bore in housing member 102 so that transverse movement of bar 105 is minimized.

Locking bar 105 is positionally fixed relative to housing member 103 by means of a cross bar 108 located at the end of housing member 103 remote from housing member 102. Specifically, cross bar 108 extends transversely through locking bar 105 into opposed openings 110 in housing member 103. Openings 110 are somewhat wider than cross bar 108, thereby providing a small degree of play in the axial position of locking bar 105 relative to housing member 103. A helical spring 109 surrounds locking bar 105 and is compressed at its ends between cross bar 108 and the opposite end wall of housing member 103. Spring 109 thus exerts an axial force on locking bar 105 tending to push the locking bar further into housing member 103. This in turn causes annular shoulder 107 to exert a force on retainer pins 106 and housing member 102 to thereby urge the abutting surfaces of the two housing members together. The abutting surface on housing member 103 has a detent pin 111 projecting therefrom toward the abutting surface of housing member 102. A pair of detent recesses 112 are formed in the abutting surface of housing member 102 and are displaced by 90 relative to the central axis of the housing members. Detent pin 111 cooperates with detent recesses 112 to provide two stable angular positions of housing member 103 relative to housing member 102. The axial force exerted by spring 109 to urge the two housing members together assures engagement between the detent pin and the appropriate detent recess at each of the two stable positions.

An actuator pin 113 projects radially outward from actuator bar 105 at a location within housing member 102. Actuator pin 113 is of such diameter as to be engaged in a slot 114 extending longitudinally from one end of hollow grip 68 on key-handle member 65. More particularly, the diameter of grip 68 is such to permit it to be inserted into the central bore extending through housing member 102. When so inserted, if slot 114 of grip 68 is aligned with actuator pin 113 on bar 105, rotation of grip 68 about the central longitudinal axis of bar 105 causes bar 105 to rotate about that axis. Rotation of actuator bar 105 in this manner produces a like rotation of housing member 103 relative to housing member 102 due to the cross bar which mechanically joins actuator bar 105 to housing member 103.

A retainer pin 115 projects radially into the central bore from housing member 102 at a location proximate annular end 104. Retainer pin 115 projects beyond the outer end of actuator pin 113 but does not contact actuator bar 105. The angular position of retainer pin 115 relative to the central axis of actuator bar 105 is such that retainer pin 115 and actuator pin 113 are aligned when the two housing members are in their stable misaligned position. When the two housing members are angularly aligned, retainer pin 115 and actuator pin 113 are misaligned by 90. The inner end of slot 114 in grip 68 is provided with a right angle bend portion 116 which is adapted to receive retainer pin 115. More particularly, assume locking mechanism to be in its locked position, as illustrated in FIGS. 1, 4 and 5, with housing members 102 and 103 misaligned by 90. Under this condition retainer pin 115 and actuator pin 113 are in alignment. 1f grip 68 is now inserted into the central bore of housing member 102, slot 114 passes over both the retainer pin and actuator pin to the position indicated most clearly in FIG. 5. Upon rotation of grip 68 so that slot 114 moves to the right (as illustrated in FIG. 5), actuator pin 113 is rotated along with slot 114 but retainer pin 11S enters the right angle portion 116 of the slot. Actuator bar and housing member 103 are thus rotated 90 along with grip 68 until the two housing members are in rotational alignment, under which circumstance auxiliary locking mechanism 100 is in its open condition. Auxiliary locking mechanism 100 can then be removed from the primary locking mechanism by simply pulling grip 68 and thereby withdrawing the auxiliary locking mechanism. This is made possible by the fact that retainer pin 115, which is secured to housing member 102, is engaged in the right angle portion 116 of slot 114. With the auxiliary locking mechanism thus removed, camming surface 107 of the key-handle can be inserted into the primary locking mechanism access slots to actuate primary bolt 21. When it is desired to re-lock enclosure 11, panel 10 is closed and primary bolt 21 is urged by spring 60 into keeper 23. Auxiliary locking mechanism 100, located on grip 68 with housing members 102 and 103 aligned, is inserted through slots 42, 43 and 44. Grip 68 is then rotated to the left (as illustrated in FIG. 5) so that slot 114 rotates actuator pin 113. Actuator bar 105 and housing member 103 are rotated along with the actuator pin by 90 to the locked condition. During this rotation the retainer pin slides through right angle portion 116 of slot 114 and aligns with actuator pin 113. With the auxiliary locking mechanism 100 thus locked, grip 68 is disengaged from the auxiliary mechanism by simply pulling the grip 69 out of the central bore as actuator pin 113 and retainer pin 115 slide through slot 114.

Opposed recesses 101 are provided in the side walls of slot 56 in primary bolt 21 to prevent locking of the auxiliary locking mechanism 100 unless bolt 21 is in its fully projected or locked position. Specifically, in the absence of recesses 101, the side walls of slot 56 provide insufficient clearance for housing member 103 to rotate to its 90 locked position relative to housing member 102. Since recesses 101 are only aligned with slots 42, 43 and 44 when bolt 21 is fully projected to its locked position, housing member 103 can only be rotated when primary bolt 21 is so projected.

A feature of the present invention having great practical significance is the use of a single element, namely key-handle 65, to open both the primary locking mechanism and the auxiliary locking mechanism 100. Another significantly practical feature of the present invention is the ability of grip 68 to retain the auxiliary mechanism 100 after it has been removed from the primary locking mechanism so that the auxiliary locking mechanism is not lost or mis-placed when the cabinet or enclosure 11 is open.

importantly the outer surface of circular end 104 in housing member 102 lies flush with the outer surface of panel 10. This enables the auxiliary locking mechanism of the present invention to block all access to the primary bolt 21 through the access slots 42, 43 and 44. ln addition, although the length of housing member 102 is shown to be slightly greater than the combined thickness of panel 10, base plate 41 and bracket 40, this representation is to facilitate an understanding of the diagram only. In fact, the preferred length of housing member 102 is substantially equal to the combined thickness of panel 10, base plate 41 and bracket 40, so that when housing member 103 is misaligned with housing member 102 it is in substantially abutting relationship at its ends with the base of bracket 40. In fact all of the spacing between the parts of the auxiliary locking mechanism and the primary locking mechanism is tight to eliminate all positional play between the locked auxiliary locking mechanism and the primary locking mechanism. This eliminates the possibility of a vandal prying the auxiliary locking mechanism out of the primary locking mechanism.

While I have described and illustrated specific embodiments of my invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.

I claim:

I. An auxiliary locking mechanism for blocking access to a primary locking mechanism which has a key hole extending through a support wall for the primary locking mechanism, said auxiliary locking mechanism comprising:

a first member adapted to fit tightly in said key hole;

a second member positioned adjacent one end of said first member so as to extend through said key hole when said first member is positioned tightly in said key hole; said first and second members being positioned along a common axis;

actuable means for rotating said second member about said axis relative to said first member and for securing said first and said second member to one another along said axis, said actuable means comprising an actuator bar extending along said common axis and fixedly secured to said second member for rotation therewith; wherein the periphery of said second member is contoured to permit removal of said first and second members from said key hole for at least one mutual rotational position of said members and to abut said support wall and thereby block removal of said members from said key hole for at least a second mutual rotational position of said members; and

wherein a bore hole is defined along said common axis through each of said first and second members, said auxiliary locking mechanism further comprismg:

means for continuously securing said actuator bar to said first member to prevent axial movement of said actuator bar relative to said first member without inhibiting rotational movement of said actuator bar about a commmon axis relative to said first member;

means for effecting rotation of said actuator bar about said common axis;

bias means for urging adjacent surfaces of said first and second members into abutting relationship; and

detent means for defining said one and said second mutual rotational positions of said first and second members.

2. The auxiliary locking mechanism according to claim 1 wherein said means for effecting rotation comprises a projection extending radially from said actuator bar within the bore hole in said first member, said mechanism further comprising a hollow tube having a longitudinally-extending slot defined at one end thereof, said tube being adapted to be inserted into the bore hole in said first member and over said actuator bar with said projection engaged in said slot, whereby rotation of said tube about said common axis exerts a torque on said projection which acts to rotate said actuator bar.

3. The auxiliary locking mechanism according to claim 2 wherein said hollow tube is an integral part of a key for said primary locking mechanism.

4. The auxiliary locking mechanism according to claim 2 further comprising:

a retainer pin projecting radially into said bore hole from said first member;

and wherein a further slot extends circumferentially about a segment of said hollow tube from a portion of said longitudinally-extending slot, said segment being at least as long as the angular spacing between said one and said second mutual rotational positions of said first and second members, said further slot being arranged to engage said retainer pin when said hollow tube is inserted into said bore hole;

said projection and said retainer pin being positioned in angular alignment when said first and second members are in said second mutual rotational position.

5. An auxiliary locking mechanism for blocking access to a primary locking mechanism which includes a support, a bolt having a latching portion mounted for longitudinal sliding movement with respect to said support, a spring means cooperating with the bolt and the support and normally maintaining the latching portion in a locked position, said bolt being provided with an elongated slot extending therethrough and axially of said bolt, the support having an entrance opening of lesser length than the elongated slot, said entrance opening registering with said slot, the end wall of the elongated slot remote from the latching portion of said bolt being inclined in a direction away from the latching position, the wall of the entrance opening in proximity to the inclined wall of the elongated slot being spaced from said inclined wall in the direction of the latching portion whereby displacement of said bolt from said locked position requires a tool having a curved end section which is inserted through said entrance opening into said elongated slot, said tool being pivoted to force said curved end section to engage said inclined wall and thereby slide said bolt out of said locked position, said auxiliary locking mechanism comprising:

a first member adapted to fit tightly in said entrance opening and flush with the wall of said entrance opening;

a second member positioned adjacent one end of said first member so as to extend through said entrance opening into said elongated slot when said first member is positioned tightly in said entrance openmg;

said first and second members being positioned along a common axis;

actuable means for rotating said second member about said axis relative to said first member and for securing said first and second members to one another along said axis;

and wherein the periphery of said second member is contoured to permit removal of said first and second members from said entrance opening for at least one mutual rotational position of said members and to abut the wall of said entrance opening and thereby block removal of said second member from entrance opening for at least a second mutual rotational position of said members.

6. The auxiliary locking mechanism according to claim wherein each of said first and second members has a bore hole defined along a common axis extending through each of said first and second members, and wherein said actuable means comprises an actuator bar extending along said common axis and fixedly secured to said second member to rotate therewith about said common axis, said auxiliary locking mechanism further comprising:

means for securing said acutuator bar to said first member to prevent axial movement of said actuator bar relative to said first member but permitting rotational movement of said actuator bar relative to said first member; and

means for effecting rotation of said actuator bar about said common axis.

7. The auxiliary locking mechanism according to claim 6 further comprising:

bias means in the form of a helical compression spring coiled about a portion of said bolt and positioned to continuously urge said bolt toward said locked position;

said bolt additionally including a channel defined therein and extending transversely of the axis of the bolt, said channel being positioned for registration with a segment of said support when said bolt is in its locked position, the width of the channel being slightly greater than said segment of said support, a portion of said helical spring engaging said support in a manner to continuously urge said bolt transversely of its axis and thereby force said channel to engage said segment of said support when said bolt is in its locked position.

8. The auxiliary locking mechanism according to claim 6 wherein said means for effecting rotation comprises a projection extending radially from said actuator bar within the bore hole in said first member, said mechanism further comprising a hollow tube having a longitudinally-extending slot defined at one end thereof, said tube being adapted to be inserted into the bore hole in said first member and over said actuator bar with said projection engaged in said slot, whereby rotation of said tube about said common axis exerts a torque on said projection which acts to rotate said actuator bar.

9. The auxiliary locking mechanism according to claim 8 wherein said hollow tube comprises a handle portion of said tool, whereby actuation of said bolt and said auxiliary locking mechanism are effected by the same integral element.

10. The auxiliary locking mechanism according to claim 9 further comprising:

a retainer pin projecting radially into said bore hole from said first member;

and wherein a further slot extends circumferentially about a segment of said hollow tube from a portion of said longitudinally extending slot, said segment being at least as long as the angular spacing between said one and second mutual rotational positions of said first and second members, said further slot being arranged to engage said retainer pin when said hollow tube is inserted into said bore hole;

said projection and said retainer pin being positioned in angular alignment when said first and second members are in said second mutual rotational positlOll. 

1. An auxiliary locking mechanism for blocking access to a primary locking mechanism which has a key hole extending through a support wall for the primary locking mechanism, said auxiliary locking mechanism comprising: a first member adapted to fit tightly in said key hole; a second member positioned adjacent one end of said first member so as to extend through said key hole when said first member is positioned tightly in said key hole; said first and second members being positioned along a common axis; actuable means for rotating said second member about said axis relative to said first member and for securing said first and said second member to one another along said axis, said actuable means comprising an actuator bar extending along said common axis and fixedly secured to said second member for rotation therewith; wherein the periphery of said second member is contoured to permit removal of said first and second members from said key hole for at least one mutual rotational position of said members and to abut said support wall and thereby block removal of said members from said key hole for at least a second mutual rotational position of said members; and wherein a bore hole is defined along said common axis through each of said first and second members, said auxiliary locking mechanism further comprising: means for continuously securing said actuator bar to said first member to prevent axial movement of said actuator bar relative to said first member without inhibiting rotational movement of said actuator bar about a commmon axis relative to said first member; means for effecting rotation of said actuator bar about said common axis; bias means for urging adjacent surfaces of said first and second members into abutting relationship; and detent means for defining said one and said second mutual rotational positions of said first and second members.
 2. The auxiliary locking mechanism according to claim 1 wherein said means for effecting rotation comprises a projection extending radially from said actuator bar within the bore hole in said first member, said mechanism further comprising a hollow tube having a longitudinally-extending slot defined at one end thereof, said tube being adapted to be inserted into the bore hole in said first member and over said actuator bar with said projection engaged in said slot, whereby rotation of said tube about said common axis exerts a torque on said projection which acts to rotate said actuator bar.
 3. The auxiliary locking mechanism according to claim 2 wherein said hollow tube is an integral part of a key for said primary locking mechanism.
 4. The auxiliary locking mechanism according to claim 2 further comprising: a retainer pin projecting radially into said bore hole from said first member; and wherein a further slot extends circumferentially about a segment of said hollow tube from a portion of said longitudinally-extending slot, said segment being at least as long as the angular spacing between said one and said second mutual rotational positions of said first and second members, said further slot being arranged to engage said retainer pin when said hollow tube is inserted into said bore hole; said projection and said retainer pin being positioned in angular alignment when said first and second members are in said second mutual rotational position.
 5. An auxiliary locking mechanism for blocking access to a primary locking mechanism which includes a support, a bolt having a latching portion mounted for longitudinal sliding movement with respect to said support, a spring means cooperating with the bolt and the support and normally maintaining the latching portion in a locked position, said bolt being provideD with an elongated slot extending therethrough and axially of said bolt, the support having an entrance opening of lesser length than the elongated slot, said entrance opening registering with said slot, the end wall of the elongated slot remote from the latching portion of said bolt being inclined in a direction away from the latching position, the wall of the entrance opening in proximity to the inclined wall of the elongated slot being spaced from said inclined wall in the direction of the latching portion whereby displacement of said bolt from said locked position requires a tool having a curved end section which is inserted through said entrance opening into said elongated slot, said tool being pivoted to force said curved end section to engage said inclined wall and thereby slide said bolt out of said locked position, said auxiliary locking mechanism comprising: a first member adapted to fit tightly in said entrance opening and flush with the wall of said entrance opening; a second member positioned adjacent one end of said first member so as to extend through said entrance opening into said elongated slot when said first member is positioned tightly in said entrance opening; said first and second members being positioned along a common axis; actuable means for rotating said second member about said axis relative to said first member and for securing said first and second members to one another along said axis; and wherein the periphery of said second member is contoured to permit removal of said first and second members from said entrance opening for at least one mutual rotational position of said members and to abut the wall of said entrance opening and thereby block removal of said second member from entrance opening for at least a second mutual rotational position of said members.
 6. The auxiliary locking mechanism according to claim 5 wherein each of said first and second members has a bore hole defined along a common axis extending through each of said first and second members, and wherein said actuable means comprises an actuator bar extending along said common axis and fixedly secured to said second member to rotate therewith about said common axis, said auxiliary locking mechanism further comprising: means for securing said acutuator bar to said first member to prevent axial movement of said actuator bar relative to said first member but permitting rotational movement of said actuator bar relative to said first member; and means for effecting rotation of said actuator bar about said common axis.
 7. The auxiliary locking mechanism according to claim 6 further comprising: bias means in the form of a helical compression spring coiled about a portion of said bolt and positioned to continuously urge said bolt toward said locked position; said bolt additionally including a channel defined therein and extending transversely of the axis of the bolt, said channel being positioned for registration with a segment of said support when said bolt is in its locked position, the width of the channel being slightly greater than said segment of said support, a portion of said helical spring engaging said support in a manner to continuously urge said bolt transversely of its axis and thereby force said channel to engage said segment of said support when said bolt is in its locked position.
 8. The auxiliary locking mechanism according to claim 6 wherein said means for effecting rotation comprises a projection extending radially from said actuator bar within the bore hole in said first member, said mechanism further comprising a hollow tube having a longitudinally-extending slot defined at one end thereof, said tube being adapted to be inserted into the bore hole in said first member and over said actuator bar with said projection engaged in said slot, whereby rotation of said tube about said common axis exerts a torque on said projection which acts to rotate said actuator bar.
 9. The auxiliary locking mechanism according tO claim 8 wherein said hollow tube comprises a handle portion of said tool, whereby actuation of said bolt and said auxiliary locking mechanism are effected by the same integral element.
 10. The auxiliary locking mechanism according to claim 9 further comprising: a retainer pin projecting radially into said bore hole from said first member; and wherein a further slot extends circumferentially about a segment of said hollow tube from a portion of said longitudinally extending slot, said segment being at least as long as the angular spacing between said one and second mutual rotational positions of said first and second members, said further slot being arranged to engage said retainer pin when said hollow tube is inserted into said bore hole; said projection and said retainer pin being positioned in angular alignment when said first and second members are in said second mutual rotational position. 